This invention relates to improvements in chemical packages serving as portable heat transfer units. It will be primarily described with reference to a unique package adapted to serve as a cooling device. However, it will be obvious that the invention embodiments are not so limited and such is not intended.
There have been many chemical packages and chemically activated devices proposed as portable heat transfer units in the prior art. However, they have had extremely limited acceptance. Their undesirable aspects have been many, two being of major importance. First, their shelf life has been extremely limited. Secondly, once energized, the period of their effective operation is normally inadequate to serve the intended purpose.